radio code

[RSJP]

does the radio /cd have to be coded to the car , my csl came with the buisness radio/cassete player , i then bought a buisness radio/cd player out of a damaged csl ,the problem im having it turns itself of after about 30 mins switches back on fine then again after 30/40 mins it turns its self of ,also it dosent switch of when the ignition is turned of
any help would be welcome
jp